656718089 has 2 divisors, whose sum is σ = 656718090. Its totient is φ = 656718088.

The previous prime is 656718077. The next prime is 656718091. The reversal of 656718089 is 980817656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 471975625 + 184742464 = 21725^2 + 13592^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656718089 is a prime.

Together with 656718091, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656718019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328359044 + 328359045.

It is an arithmetic number, because the mean of its divisors is an integer number (328359045).

Almost surely, 2^656718089 is an apocalyptic number.

It is an amenable number.

656718089 is a deficient number, since it is larger than the sum of its proper divisors (1).

656718089 is an equidigital number, since it uses as much as digits as its factorization.

656718089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 50.

The square root of 656718089 is about 25626.5114481078. The cubic root of 656718089 is about 869.2132266989.

The spelling of 656718089 in words is "six hundred fifty-six million, seven hundred eighteen thousand, eighty-nine".